Hydrogen-induced crack resistant 2000MPa-grade zinc-based plated steel plate, manufacturing method thereof, hot forming method and part

Abstract

The invention provides a hydrogen induced crack resistant 2000MPa grade zinc-based coated steel plate, which comprises a base plate and a coating, the base plate comprises the following components in percentage by weight: 0.32%-0.40% of C, 0.15%-0.45% of Si, 1.30%-2.50% of Mn, less than or equal to 0.02% of P, less than or equal to 0.02% of S, 0.03%-1.80% of Al, 0.02%-0.10% of Nb, 0.02%-0.15% of Ti, 0.002%-0.005% of B, 0.15%-0.60% of Cr, and Fe and other inevitable impurities; and the plating layer comprises the following components in percentage by mass: 0.15%-3.50% of Al and the balance of Zn. The invention further provides a manufacturing method of the hydrogen induced crack resistant 2000 MPa grade zinc-based plated steel plate. The manufacturing method comprises the steps of smelting, casting, hot rolling and hot dipping. The invention further discloses a hot stamping method of the hydrogen induced crack resistant 2000MPa-grade zinc-based coating steel plate. The hot stamping method comprises the steps of steel plate heating, steel plate cooling and hot stamping. According to the hot stamping forming part produced through the method, the tensile strength of the steel plate is larger than 2000 MPa, the yield strength is larger than 1400 MPa, the elongation is larger than 5%, and the delayed fracture resistance is excellent.

Description

Technical Field

[0001] The invention relates to a coated steel plate, in particular to a hot stamping method for a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking, and a steel plate and a hot-formed component thereof. Background Art

[0002] The automotive industry is transforming towards new energy. One of the characteristics of new energy vehicles is that they must carry batteries. The weight of the battery varies with the energy density and range, but it is very heavy overall. This requires the structure of new energy vehicles to be extremely lightweight, and 2000MPa grade aluminum-silicon coated hot-formed steel meets this trend.

[0003] However, 2000MPa grade aluminum-silicon coated hot-formed steel has the problem of hydrogen induced cracking. The present invention comprehensively addresses several aspects, including steel plate composition design, interface design between the coating and the steel substrate, and hot stamping forming process, to solve the problem of hydrogen induced cracking in 2000MPa grade aluminum-silicon coated hot-formed steel.

[0004] Since hot forming is carried out under high temperature conditions, the steel plate will inevitably oxidize, and subsequent methods such as sandblasting and pickling are required to remove the iron oxide scale. To solve this problem, aluminum-silicon coated hot-formed steel plates have been developed. The aluminum-silicon coating can provide protection for the steel plate at high temperatures and avoid the formation of iron oxide scale. However, the aluminum-iron intermetallic compound generated by the reaction between the coating and the steel substrate during hot stamping is a brittle and hard phase and cannot provide electrochemical protection for the substrate.

[0005] Therefore, zinc-based coated hot-formed steel plates were proposed. Compared with traditional aluminum-silicon coated hot-formed steel plates, zinc-based coated hot-formed steel plates have better corrosion resistance. However, due to the low melting point of iron-zinc compounds, liquid phase brittleness problems will occur during the stamping process, causing parts to crack and fail.

[0006] To solve these problems, the present invention provides a 2000MPa grade zinc-based coated steel plate hot stamping method and a zinc-based coated hot-formed steel plate. The formed parts have the protective effect of pure zinc coating on the steel plate, while solving the liquid phase corrosion of the pure zinc coating on the steel substrate, and have the ability to resist delayed fracture. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a hot stamping method for a 2000MPa grade zinc-coated steel plate resistant to hydrogen-induced cracking, and the steel plate and hot-formed parts thereof. The hot stamping parts produced by the method of the present invention have no liquid phase brittleness and liquid phase cracks, have good resistance to hydrogen-induced cracking, strength and toughness, and at the same time have excellent corrosion resistance.

[0008] The object of the invention is achieved in this way:

[0009] The present invention provides a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking, comprising a substrate and a coating, as follows:

[0010] The zinc-based coated steel plate substrate has chemical compositions, by mass percentage, including: C: 0.32%-0.40%, Si: 0.15%-0.45%, Mn: 1.30%-2.50%, P≤0.02%, S≤0.02%, Al: 0.03%-1.80%, Nb: 0.02%-0.10%, Ti: 0.02%-0.15%, B: 0.002%-0.005%, Cr: 0.15%-0.60%, Fe and some other inevitable impurities.

[0011] Furthermore, the substrate composition also includes one or more of the following elements: Mo≤1.00%, Cu≤0.50%, Ni≤1.00%, V≤0.20%, (Al+Si)≥0.2%.

[0012] Furthermore, the coating of the zinc-based coated steel sheet comprises, by mass percentage, chemical compositions of: Al: 0.15% to 3.50%, and the remainder Zn.

[0013] Furthermore, the coating composition also includes one or more of: Mg: 1.0% to 2.0%, Si: 0.05% to 0.50%, Ti: 0.03% to 0.50%, Re: 0.01% to 0.10%, Mn: 0.5% to 3.0%, Ni: 0.5% to 5.0%.

[0014] The composition design reasons of the elements in the steel plate substrate are as follows:

[0015] C: 0.32%~0.40%

[0016] As the main alloying element, C contributes most to the strength of quenchable martensitic steel, providing strength, improving hardenability, increasing the content and hardness of martensite. At the same time, C can expand the austenite phase and reduce the liquid phase brittleness caused by Zn. The C content ranges from 0.32% to 0.40%. If the content is too low, the strength cannot reach 2000MPa. If the content is too high, the strength is too high and the toughness is reduced.

[0017] Mn: 1.30%~2.50%

[0018] The main function of Mn is to expand the austenite phase area, so that the zinc-based coated hot-formed steel plate can be hot stamped in a lower temperature range and can also obtain martensite structure. The Mn element can improve the strength and hardenability of steel and improve the toughness of steel. The Mn content range is 1.30% to 2.50%. If the content is too low, the martensite transformation temperature is high and the strength is low. If the content is too high, selective oxidation will occur, resulting in poor hot dip performance and increased costs.

[0019] Si: 0.15% to 0.45%

[0020] Si mainly inhibits the appearance of cementite, ensures the stability of low-temperature austenite, and strengthens the steel matrix. Si: 0.15% to 0.45%. When Si content is lower than 0.15%, the stability of austenite decreases. When Si content is higher than 0.45%, a selective oxide layer will be formed on the surface of the steel plate, affecting the hot-dip coating performance.

[0021] Al: 0.03%~1.80%

[0022] The role of Al is similar to that of Si. It is better to use it together with Si to inhibit the appearance of cementite and ensure the stability of low-temperature austenite. However, the Al element will reduce the austenite phase area. At the same time, Al can form AlN precipitation with N in steel, refine the grains, act as a permanent hydrogen trap, absorb hydrogen atoms, and improve the delayed fracture resistance. Al: 0.03% to 1.80%. If the content is higher than 1.80%, it will affect the low-temperature stability of austenite. If the content is lower than 0.03%, it cannot ensure a good deoxidation effect and will increase the inclusion content in the steel.

[0023] Ti: 0.02% to 0.15%, B: 0.002% to 0.005%, Cr: 0.15% to 0.60%

[0024] To ensure hardenability, Ti, Cr and B are added.

[0025] Ti: 0.02-0.15%. If the content is lower than the lower limit, a good grain refinement effect cannot be guaranteed, and the weld structure will also coarsen during welding; if the content is higher than the upper limit, excessive and coarse titanium carbonitride precipitation will be generated, affecting the toughness of the steel plate.

[0026] B: 0.002%~0.005%, mainly to improve hardenability. If the content is too low, the effect is not obvious, and if the content is too high, it will affect the toughness of the steel.

[0027] Cr: 0.15%~0.60%, mainly to improve hardenability, too low content

[0028] Si: 0.15%~0.45%, Mn: 1.30%~2.50%

[0029] Due to the solute drag effect, it is difficult for Cr, Si, and Mn elements to diffuse and migrate in steel, which can prevent the corrosion of the steel matrix by the liquid Zn in the coating during the hot stamping heating and insulation process, reduce the liquid phase brittleness, and thus improve the performance of the zinc-based hot-formed steel sheet. The effect is not obvious, and too high a content will affect the hot-dip performance of steel, causing leakage plating, and increasing costs.

[0030] Cu≤0.50%

[0031] Adding Cu improves the corrosion resistance of steel, thereby preventing the penetration of H and improving the delayed fracture resistance of steel. The dispersed CuS precipitation can act as a permanent hydrogen trap in steel, adsorbing H atoms, avoiding hydrogen embrittlement, and improving the delayed fracture resistance of steel.

[0032] Mo≤1.00%, Nb: 0.02~0.10%

[0033] The addition of Mo and Nb strengthens the steel matrix and refines the grains.

[0034] The addition of Mo, Ti and Nb can form fine dispersed precipitates such as TiN, TiC and NbC in the steel, forming hydrogen traps during service and improving the delayed fracture resistance of the steel.

[0035] Ni≤1.00%. During the hot stamping heating and insulation process, since Ni atoms are difficult to migrate, they can well resist the erosion of liquid Zn on the grain boundaries of the steel matrix. The addition of Ni can improve the toughness of the steel, improve the corrosion resistance of the steel, reduce the diffusion rate of H, and improve the delayed fracture resistance.

[0036] V≤0.20%. The addition of V can form VC precipitation and refine the grains. Nano-precipitated VC can be a permanent hydrogen trap in the steel, adsorbing H and improving the delayed fracture resistance.

[0037] The reasons for designing the composition of elements in the zinc-based coated steel plate coating are as follows:

[0038] Al: 0.15%~3.50%

[0039] Al: The addition of Al can generate aluminum oxide to cover the surface of the coating during the hot forming heating and heat preservation of the steel plate, forming a protective layer to prevent further oxidation of the coating. The Al element will form Fe-Al compounds at the interface between the steel plate and the coating. The Fe-Al compounds delay the erosion of the liquid zinc on the grain boundary of the steel plate during the hot stamping heating and heat preservation process, reducing the liquid phase brittleness.

[0040] Mg: 1.0%~2.0%

[0041] Mg: The addition of Mg element can greatly improve the corrosion resistance of the coating. At the same time, the magnesium oxide generated by magnesium oxidation can also cover the surface of the coating to form a protective layer to prevent further oxidation of the coating.

[0042] Si: 0.05% to 0.50%

[0043] Si: Si is enriched in the intermetallic compound layer, which hinders the mutual diffusion of Fe and Zn atoms through the liquid phase channel, and can form a compact inhibition layer structure, thereby reducing or even eliminating the liquid phase corrosion of the coating on the steel substrate, refining the structure of the coating and improving the coating performance.

[0044] Ti: 0.03%~0.50%

[0045] Ti: The addition of Ti can improve the corrosion resistance of the coating. In addition, Ti can form a protective film of titanium oxide, which has a strong bond with the substrate, good protection performance, and can repair damage by itself. Adding Si and Ti at the same time can generate a more compact inhibition layer and improve the ability of the steel plate to resist liquid phase corrosion. Ti can form an intermetallic compound with Al to improve the hardness of the coating.

[0046] Re: 0.01%~0.10%

[0047] Re: Improve the corrosion resistance of the coating, refine the grains, and facilitate the formation of a dense oxide film on the surface of the coating, providing protection during hot stamping.

[0048] Mn: 0.5%~3.0%

[0049] Mn: Improves the corrosion resistance of the coating, refines the grains, and increases the hardness of the coating.

[0050] Technical solution 2 of the present invention provides a method for manufacturing a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking, including smelting, casting, hot rolling, pickling and cold rolling, and hot-dip plating.

[0051] Hot rolling process:

[0052] Heating at 1220±40℃, keeping warm for 180±90 minutes, rough rolling at 1100±40℃, finishing rolling at 1060±40℃, final rolling at 870±40℃, and coiling at 450~750℃; heating at 1220±40℃, keeping warm for 180±90 minutes to ensure that the second phase precipitates in the steel are fully dissolved and the segregation in the steel is homogenized; rough rolling at 1100±40℃, finishing rolling at 1060±40℃ to ensure the deformation capacity and dephosphorization effect of the steel; final rolling at 870±40℃ to ensure the effect of grain refinement and reduce banded structure, coiling at 450~750℃ to ensure the uniform dispersion distribution of the second phase precipitation, no martensitic structure is generated, and a fine metallographic structure is obtained, which provides a basis for the subsequent final structure with high bending performance. At the same time, the thickness of the oxide scale is thin and easy to be removed by pickling.

[0053] Pickling and cold rolling:

[0054] Pickling is used to completely remove the iron oxide scale. The cold rolling reduction rate is 30% to 70%. Rolling is difficult when the reduction rate is greater than 70%, and the grain refinement effect is not obvious when the reduction rate is less than 30%.

[0055] Hot dip coating process:

[0056] The plating solution composition is one or more of Al: 0.15% to 3.50%, Mg: 1.0% to 2.0%, Si: 0.05% to 0.50%, Ti: 0.03% to 0.50%, Re: 0.01% to 0.10%, Mn: 0.5% to 3.0%, and the rest is Zn.

[0057] The hot-dip heating temperature is controlled at 750-900°C, and the zinc pot temperature is 450-520°C. The steel plate is pre-oxidized during the heating process, specifically in the temperature range of 600-750°C, using an oxidizing atmosphere (a furnace atmosphere with a high dew point or a furnace atmosphere containing oxygen) to pre-oxidize the surface of the steel plate, so that an oxide film mainly composed of iron oxide is generated on the surface of the steel plate, which is reduced to active iron during the subsequent heating and insulation process. The active iron is easy to react with the aluminum element in the zinc pot to produce an alloy layer mainly composed of aluminum and iron.

[0058] Technical solution three of the present invention provides a hot forming method for a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking, comprising heating the steel plate, cooling the steel plate, and hot stamping.

[0059] 1) Steel plate heating: The zinc-based hot-formed steel plate is sent into a heating furnace for heating, the heating and holding time is 180 seconds to 600 seconds in total, and the heating temperature is 800-930° C., preferably 850-890° C.;

[0060] If the heating time is less than 180 seconds, the austenitization of the steel plate is not sufficient, and the reaction between the coating and the steel matrix is ​​not sufficient, and it cannot be completely converted into Fe-Zn intermetallic compounds. If the heating time is more than 600 seconds, it will cause the coarsening of austenite grains and deteriorate the performance of the steel. At the same time, the Fe-Zn intermetallic compounds in the coating are all converted into α-Fe (Zn) solid solutions, reducing the corrosion resistance of the steel and forming a very thick α-Fe layer, which will greatly reduce the strength of the steel. If the heating temperature is less than 800℃, austenitization cannot be achieved, and the alloying of the coating is not sufficient. If the heating temperature is higher than 930℃, it is consistent with the effect of too long a holding time, and it will also cause zinc evaporation.

[0061] 2) Steel plate cooling: After the steel plate is heat-insulated, it is cooled to the hot stamping temperature and stamping begins. The target temperature range for cooling is 500-850°C, preferably 600-720°C, and the cooling rate is greater than 10°C / s;

[0062] If the cooling target temperature is lower than 500℃, austenite will decompose. If the cooling target temperature is higher than 850℃, Fe-Zn intermetallic compounds will be in liquid state, which will cause liquid phase embrittlement. This problem can be completely avoided below 720℃. The purpose of cooling rate greater than 10℃ / s is to ensure the presence of austenite in the steel.

[0063] Through low-temperature hot stamping, most of the grains (more than 80%) are controlled to form small-angle grain boundaries and subgrain boundaries (angle less than 20 degrees), thereby improving the strength of the grain boundaries and reducing cracking and failure along the grain boundaries.

[0064] 3) Hot stamping: Hot stamping is performed immediately after the steel plate is cooled to the hot stamping temperature. The hot stamping cooling rate is greater than 15°C / s, and the cooling end temperature is controlled at 120-280°C, preferably 150-220°C. The strength of the steel plate is greater than 2000MPa, and the elongation is greater than 5%. The coating is completely transformed into an iron alloy layer, without coating evaporation, liquid phase erosion, and hard Fe-Al intermetallic compounds.

[0065] The cooling end temperature is controlled above 120°C, and the residual heat can be used to age the parts after stamping is completed, which can improve the toughness of the parts to a certain extent; the cooling end temperature is controlled below 280°C because the transformation of martensite is incomplete above 280°C, and too high a residual heat aging temperature will reduce the strength of the steel.

[0066] Furthermore, the heating temperature during the steel plate heating process is 850-890°C; the cooling target temperature range during the steel plate cooling process is 600-720°C; and the cooling end point temperature during the hot stamping process is 150-200°C.

[0067] Technical solution four of the present invention provides a hot-formed component made of a 2000MPa grade zinc-based coated steel plate that is resistant to hydrogen-induced cracking. The steel base structure of the component is more than 97% martensite structure, and the remainder is composed of ferrite + residual austenite + bainite (residual austenite film (content of 0.5% to 1.5%), ferrite + bainite structure (1.5% to 2.5%)). The microstructure of the surface of the component has four layers (from the surface to the steel matrix in sequence), the first layer is the surface oxide layer: aluminum oxide + zinc oxide + iron oxide + manganese oxide; the second layer is the iron-zinc intermetallic compound layer; the third layer, an α-Fe (Zn) solid solution layer, the Zn content is greater than 5%, the thickness range is 10um to 50um, and the fourth layer is the steel matrix layer.

[0068] The second intermetallic compound layer and the third α-Fe(Zn) solid solution layer will preferentially electrochemically corrode the substrate, providing cathodic protection for the substrate. The α-Fe(Zn) solid solution layer has good plasticity and toughness, which can reduce or even eliminate the generation and expansion of microcracks and improve the toughness of the product.

[0069] The beneficial effects of the present invention are:

[0070] The present invention emphasizes the role of Nb, V, Ti and rare earth elements in composition, forming permanent hydrogen traps, which can withstand the action of extremely high concentrations of hydrogen atoms without hydrogen-induced cracking during service, and emphasizes the precipitation of vanadium carbonitride; the organization emphasizes more than 97% martensite structure, and at the same time, there is a residual austenite film (content of 0.5% to 1.5%) between the martensite laths; a small amount of ferrite + bainite structure (1.5% to 2.5%).

[0071] 1. The present invention provides a zinc-based coated steel plate for hot forming. After hot pressing, the steel plate has a tensile strength greater than 2000 MPa, a yield strength greater than 1400 MPa, an elongation greater than 5%, and excellent delayed fracture resistance.

[0072] 2. The coating is completely transformed into an iron alloy layer, with no coating evaporation, no liquid phase corrosion, and no hard Fe-Al intermetallic compounds. The structure of the steel plate is martensite (more than 97% by volume) + residual austenite (0.5% to 1.5% by volume) + (ferrite + bainite) (remainder).

[0073] 3. The hot stamped steel plate can meet the requirement of four-point bending without cracking for 120 hours (in hydrochloric acid solution with a pH value of 1). DETAILED DESCRIPTION

[0074] The present invention will be further described below by way of examples.

[0075] The chemical compositions of the steel of the present invention are shown in Tables 1, 2, 3, 4 and 5.

[0076] A method for manufacturing a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking comprises smelting, casting, hot rolling and hot-dip coating.

[0077] Hot rolling process:

[0078] Heating at 1220±40℃, keeping warm for 180±90 minutes, rough rolling at 1100±40℃, finishing rolling at 1060±40℃, final rolling at 870±40℃, coiling at 450~750℃;

[0079] Hot dip coating process:

[0080] The plating solution composition is Al: 0.15% to 3.50%, and the rest is Zn; it also includes one or more of Mg: 1.0% to 2.0%, Si: 0.05% to 0.50%, Ti: 0.03% to 0.50%, Re: 0.01% to 0.10%, and Mn: 0.5% to 3.0%;

[0081] The hot-dip galvanizing heating temperature is 750-900°C, and the zinc pot temperature is 450-520°C; the steel plate is pre-oxidized during the heating process, specifically in the temperature range of 600-750°C.

[0082] A hot stamping method for a 2000MPa grade zinc-based coated steel plate resistant to hydrogen-induced cracking comprises heating the steel plate, cooling the steel plate and hot stamping.

[0083] Steel plate heating:

[0084] The zinc-based coated hot-formed steel sheet is sent into a heating furnace for heating, the heating and holding time is 180 seconds to 600 seconds in total, and the heating temperature is 800-930°C;

[0085] Steel plate cooling:

[0086] After the steel plate is insulated, it is cooled to the hot stamping temperature and stamping begins. The target temperature range for cooling is 500-850°C, and the cooling rate is greater than 10°C / s.

[0087] Hot stamping:

[0088] Hot stamping is performed immediately after the steel plate is cooled to the hot stamping temperature. The hot stamping cooling rate is greater than 15°C / s, and the cooling end temperature is between 120 and 280°C.

[0089] Furthermore, the heating temperature during the steel plate heating process is preferably 850-890°C; the cooling target temperature range during the steel plate cooling process is preferably 600-720°C; and the cooling endpoint temperature during the hot stamping process is preferably 150-200°C.

[0090] A component made by hot stamping of a hydrogen-cracking resistant 2000MPa zinc-based coated steel plate, wherein the component steel base structure is more than 97% martensite structure, 0.5% to 1.5% ferrite structure, and the content of residual austenite + bainite structure is 1.5% to 2.5%.

[0091] Furthermore, the microstructure of the component surface has four layers, namely 1, 2, 3, and 4 layers from the surface to the steel matrix. The 1st layer is the surface oxide layer: aluminum oxide + zinc oxide + iron oxide + manganese oxide; the 2nd layer is the iron-zinc intermetallic compound layer; the 3rd layer is the α-Fe (Zn) solid solution layer, with a Zn content greater than 5% and a thickness ranging from 10um to 50um. The 4th layer is the steel matrix layer.

[0092] Furthermore, the thermoformed component has a tensile strength greater than 2000 MPa, a yield strength greater than 1400 MPa, an elongation greater than 5%, and does not crack after four-point bending for 120 hours.

[0093] Table 1: Chemical element composition of the coating in the example (wt%)

[0094] Al Mg Ti Si Mn Re Ni Zn 1 0.20 1.1 margin 2 0.21 0.28 0.06 margin 3 0.17 1.1 1.30 margin 4 2.35 1.6 0.07 0.22 margin 5 1.21 0.13 2.3 margin 6 0.19 0.02 margin 7 3.2 1.3 0.31 3.6 margin 8 0.21 1.9 0.43 0.08 margin 9 0.22 0.70 margin 10 0.16 0.60 margin

[0095] Table 2: Chemical composition of example steel (wt%)

[0096]

[0097]

[0098] Table 3 Example steel process parameters:

[0099]

[0100] Table 4: Hot stamping process parameters and properties of example steel

[0101]

[0102] Table 5 Steel matrix structure of hot stamping parts

[0103]

[0104] As can be seen from the above, the strength of the steel plate of the present invention is greater than 2000MPa, and the elongation is greater than 5%. The coating is completely transformed into an iron alloy layer, there is no coating evaporation phenomenon, no liquid phase corrosion phenomenon, and no hard Fe-Al intermetallic compound. The structure of the steel plate is martensite + a small amount of (ferrite + residual austenite + bainite).

[0105] In order to describe the present invention, the present invention is appropriately and fully illustrated by the examples in the above. The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made should be included in the protection scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A 2000MPa grade zinc-based coated steel sheet resistant to hydrogen-induced cracking, comprising a substrate and a coating, characterized in that: The substrate comprises the following components by weight percentage: C: 0.32%-0.40%, Si: 0.15%-0.45%, Mn: 1.30%-2.50%, P≤0.02%, S≤0.02%, Al: 0.03%-1.80%, Nb: 0.02%-0.10%, Ti: 0.02%-0.15%, B: 0.002%-0.005%, Cr: 0.15%-0.60%, Fe and some other inevitable impurities.

2. The 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 1, characterized in that: The substrate component also includes one or more of the following elements: Mo≤1.00%, Cu≤0.50%, Ni≤1.00%, V≤0.20%; the substrate component (Al+Si)≥0.2%.

3. The 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 1, characterized in that: The coating comprises the following components by mass percentage: Al: 0.15% to 3.50%, and the rest is Zn.

4. The 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 3, characterized in that: The components also include one or more of the following elements: Mg: 1.0% to 2.0%, Si: 0.05% to 0.50%, Ti: 0.03% to 0.50%, Re: 0.01% to 0.10%, Mn: 0.5% to 3.0%, Ni: 0.5% to 5.0%.

5. A method for manufacturing a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking as claimed in any one of claims 1 to 4, comprising smelting, casting, hot rolling, pickling and cold rolling, and hot dip coating, characterized in that: Hot rolling process: Heating at 1220±40℃, keeping warm for 180±90 minutes, rough rolling at 1100±40℃, finishing rolling at 1060±40℃, final rolling at 870±40℃, coiling at 450~750℃; Pickling and cold rolling: Cold rolling reduction rate 30% to 70%; Hot dip coating process: The hot-dip galvanizing heating temperature is 750-900°C, and the zinc pot temperature is 450-520°C; the steel plate is pre-oxidized during the heating process, specifically in the temperature range of 600-750°C.

6. A hot stamping method for a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking as claimed in any one of claims 1 to 4, characterized in that: Including steel plate heating, steel plate cooling, hot stamping, Steel plate heating: The zinc-based hot-formed steel plate is sent into a heating furnace for heating, the heating and holding time is 180 to 600 seconds in total, and the heating temperature is 800 to 930°C; Steel plate cooling: After the steel plate is insulated, it is cooled to the hot stamping temperature and then stamping begins. The cooling rate is greater than 10°C / s, and the cooling hot stamping temperature range is 500-850°C. Hot stamping: Hot stamping is performed immediately after the steel plate is cooled to the hot stamping temperature. The hot stamping cooling rate is greater than 15°C / s, and the cooling end temperature is between 120 and 280°C.

7. The hot stamping method of a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 6, characterized in that: The heating temperature during the steel plate heating process is 850-890° C.; the cooling target temperature range during the steel plate cooling process is 600-720° C.; and the cooling end point temperature during the hot stamping process is 150-200° C.

8. A component made by hot stamping of a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking as claimed in claim 6, characterized in that: The steel matrix of the component is more than 97% of martensite, 0.5% to 1.5% of ferrite, and 1.5% to 2.5% of retained austenite + bainite.

9. The component made by hot stamping method of a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 8, characterized in that: There are four layers of microstructure on the surface of the component, namely 1, 2, 3, and 4 layers from the surface to the steel matrix. The 1st layer is the surface oxide layer: aluminum oxide + zinc oxide + iron oxide + manganese oxide; the 2nd layer is the iron-zinc intermetallic compound layer; the 3rd layer is the α-Fe (Zn) solid solution layer, with a Zn content greater than 5% and a thickness ranging from 10 to 50um. The 4th layer is the steel matrix layer.

10. The component made by hot stamping method of a 2000MPa grade zinc-based coated steel sheet resistant to hydrogen induced cracking according to claim 8, characterized in that: The thermoformed component has a tensile strength greater than 2000 MPa, a yield strength greater than 1400 MPa, an elongation greater than 5%, and does not crack after four-point bending for 120 hours.

Images